how much is 1 day pass to the park

It varies by time of year and discounts. Here is the link: https://www.universalorlando.com/web/en/us/tickets-packages/park-tickets

Robert Cardwell is right, the cost does vary by the time of year and available discounts. I hear it's really cheap in February

For 2 people adult 1 day pass 2 parks, US $380 direct cashier

You can get cheaper prices on the internet